SAULT STE. MARIE, Mich. – People who visit the Soo Locks can easily get a sinking feeling. Or, on the opposite end of the spectrum, a heightened feeling.

Either way, both are fun options that tourists can partake in with a visit to not only one of the world’s great engineering marvels, but also a critical component of the U.S. economy.

Built in 1855, the Soo Locks are canals that allow large shipping vessels to pass through Lake Huron to Lake Superior, and also from Minnesota to the Atlantic Ocean, and vice versa.

They are located along the St. Marys River in between Sault Ste. Marie, Michigan, and Sault Ste. Marie, Ontario, Canada.

There is a 21-foot difference in the water levels of Lake Superior and Lake Huron, and the Locks help boats get lowered and raised, depending on their direction, by filling up and draining water to help ships adapt to the new water levels.

The best part? Tourists can experience what it's like to be on one of those ships.

But having the experience of being raised and lowered in one of the Locks isn't the only perk.

Depending on what type of boat tour is booked, setting sail on the Soo Locks can involve highlights such as a buffet dinner, fireworks, a chance to move besides massive freighters and under the massive International Bridge that separates the U.S. and Canada, and a chance to (sort of) visit another country without a passport.

When on a boat, you technically sail for a brief time into Canadian waters, although you never set foot on Canadian soil.

Don't like going on boats or get seasick doing so? No worries!

There is a public observation deck along the Locks that allows people to view the action.

Because without the Soo Locks, the U.S. economy would plunge into a deep recession.

In 2016, the U.S. Department of Homeland Security released a report saying that just a six-month shutdown of the Soo Locks would result in 11 million lost jobs across the country.

The Soo Locks see 90% of the world’s iron ore, according to its website, move through them, eventually reaching destinations such as steel mills. Coal and other resources are also shipped regularly through the Locks.

Roughly 7,000 vessels pass through the Locks each year, hauling an estimated 86 million tons of cargo to industries in the U.S. and Canada.

The Locks helped support more than 123,000 jobs in the U.S. and Canada and $22.6 billion in economic activity in the U.S., according to the Saint Lawrence Seaway in 2018.

There you have it.

One visit to the Soo Locks will provide a fun and rare up-and-close experience to how a vital aspect of the U.S. economy works.